<!DOCTYPE html>
<html lang='en'>
<head>
    <meta charset='UTF-8'>
    <meta name='viewport' content='width=device-width, initial-scale=1.0'>
    <title>Document</title>
    <script type='text/javascript' src='js/vue.js'></script>
    <style>
    .aa{
        color:red;
    }
    </style>
</head>
<body>
    <div id='app'>
        {{msg}}
        <p  class='qq' >我是红色</p>
        ========数组
        <div :class="[active,'active2']">方式一:calss="aa  active2"</div>
        <hr>
        <div :class="[flag2?active:'','active2']">方式2:calss="aa  active2"</div>
        <hr>
        <div :class="[flag2?active:'',{active2:flag3}]">方式3====class="aa"</div>

        <hr>对象
        <div :class="{aa:flag2}">方式4===calss='aa'</div>
    </div>
    <script type='text/javascript'>
        var vm = new Vue({
            el: '#app',
            data: {
                msg: 'Hello Vue',
                url:'./11.png',
                active:'aa',
                active2:'bb',
                flag2:true,
                flag3:false
            }
        });
    </script>
</body>
</html>